Long on the sidelines of its more publicity hungry diseases, typhoid problems need to be tackled immediately
TYPHOID fever (TF) remains an important public health problem in many developing countries. It is responsible for about 16 million cases and more than 600,000 deaths a year. Almost 80 per cent of cases and 80 per cent of deaths occur in Asia while others occur in Africa and Latin America.
The mean incidence of the disease ranges from 150/100,000/year in South America to 900/100,000/year in Asia (WHO report 1996). At the same time, according to the report, the peak incidence of typhoid fever is among school age of children.
HISTORY: It was in 1880 Eberth discovered the etiologic agent tissues from a patient infected with Typhoid Fever. In 1884 Gaffky first cultivated and isolated Salmonella Typhi in pure culture from the spleens of infected patients. In 1896, Pfeiffer and Kolle, in Germany and Wright in England prepared the first vaccine for human.
In 1906, 3000 New York state residents contracted the contagious and life threatening bacterial illness. An Irish cook named Mary Maloon seems to have infected only a small percentage of these people, yet she became so identified in the public mind with the epidemic that she was dubbed Typhoid Marry and quarantined for life on an island in the Hudson River.
SPREAD OF DISEASE: Humans are the only reservoir of Salmonella Typhi infection as well as the early natural host. The transmission of micro-organism occurs when susceptible hosts ingest contaminated food or water. The highest incidence usually occurs where sewage water contaminates water supplies serving large populations.
In developing countries like Pakistan, drinking water represents the most common vehicle of transmission of disease.
Other than contaminated water, chronic carriers transmit the micro-organism to food through a breakdown in proper practices of personal hygiene in food preparation.
CAUSES OF TYPHOID FEVER: The bacterium responsible for typhoid fever is Salmonella typhi. There are other Salmonellas such as the Salmonella paratyphi A, B and C. The genus Salmonella includes a large number of gram negative pathogens of human as well a mammals.
Currently, more then 2300 stereotypes of Salmonella are known. Three species exists in the genus Salmonella: S. enteritidis, S. choleraesuis and S. typhi.
S. typhi contains O and Vi antigens and its peritrichous flagella bears the flagellar H antigen. The bacteria is motile. The microorganism can survive several months in soil or water.
The bacteria that causes typhoid and paratyphoid fever both spread through contaminated food or water and occasionally through direct contact with someone who is already infected. In developing nations, where typhoid and paratyphoid are endemic, most cases result from contaminated drinking water and poor sanitation.
CLINICAL PRESENTATION: The classical evolution of typhoid fever infection has different phases, and these are characteristics of about 50 per cent of typhoid fever cases.
INCUBATION PHASE: This phase may last from seven to 21 days. In this phase there is no sign and symptoms.
INVASIVE PHASE: In this phase an individual can have fever, headache and abdominal pain that gradually increases over the course of two to three days, dissociated pulse, persistent headache, asthenia, dizziness, nausea and epistaxis. Physically a patient feels hot dry skin, abdominal tenderness and under the examining fingers, a sensation of displacing air and fluids filled loops of bowel.
Some times spleenomegaly and general lymphadenopathy may be present.
STATUS PERIOD: Clinical signs consist of a consistently high fever, weakness, fatigue and weight loss.
After one week, rose spots appear on the skin over the anterior chest and upper abdominal wall. The rash is temporary, usually disappearing within three or four days. Diarrhoea can appear looking like melon juice or pea soup, or severe due to constipation the abdomen may become distended. Superficial ulceration of the soft palate is inconstant.
COMPLICATIONS: Nearly one-third of the people with typhoid fever develop complications.
The most serious complication is intestinal bleeding or perforation. It usually develops in the third week of illness and marked by a sudden drop in the blood pressure and shock and appearance of blood in stools.
The incidence of life-threatening intestinal complications is between three per cent and 10 per cent. Some less common complications includes:
Inflammation of the heart muscle (myocarditis). Infection and inflammation of the brain membranes (meningitis).
Infections of the spine (osteomyelitis).
Pneumonia.
CARRIER STATE: A typhoid fever patient can shed organisms in his stool over a period of at least one year, after recover from the disease.
Carriage is usually without symptoms. Identification of a carrier is done by stool testing. A typhoid fever patient should wash his hands thoroughly after using the bathroom and flush faeces with plenty of water.
SCREENING AND DIAGNOSIS: Clinical manifestations are not enough to diagnose the typhoid fever. Some laboratory analysis needs to be done.
For the identification of bacteria Salmonella typhi or S. paratyphi blood or body fluids or tissues should be culture.
A small sample of blood, stool, urine or bone marrow is placed on a special medium that encourage the growth of bacteria and then after sometime the culture is checked under a microscope for the presence of typhoid bacteria.
Bone marrow culture is the gold standard for bacteriological confirmation of disease.
TREATMENT: Treatment management of typhoid fever involves symptomatic support, antibiotic therapy and prophylactic measures.
In symptomatic support plenty of fluids are recommended to restore electrolytes balance. Analgesic drugs may be used to alleviate abdominal pain and cramps.
Antibiotic therapy is the main weapon against the disease.
Cloramphenicol, ampicillin and trimethoprim sulfamethoxazole are the three classic antibiotics used against typhoid fever.
However, there is the incidence of multi-drug resistance to the bacteria of typhoid fever. Now due to this drug resistance ceftriaxone or ciprofloxacine are recommended.
PREVENTION: In many developing countries, like Pakistan, it may be difficult to achieve the public health goals that prevent and control typhoid fever such as safe drinking water, improved sanitation and adequate medical care.
In such a type of environment vaccinating population is the best way to control typhoid fever.
Today, vaccines are a potent means of prevention against typhoid fever. There are different types of vaccines are available.
Whole cell typhoid vaccine.
Oral live attenuated vaccine.
Polysaccharide vaccine (purified Vi antigen)
A parenteral polysaccharide vaccine that contains the Vi antigen, a virulence factor found on the surface of the bacteria is recommended. Its one shot protection lasts for at least three years, is safe and economical. To minimize the economic burden, vaccination is the best solution. The cost of hospitalization, medication and absenteeism from job or school is higher then the cost of a single shot of vaccine for typhoid fever.
High risk population for vaccination are:
Travellers.
Military personnel.
School aged children.
Laboratory workers.
Kitchen staff of hotels and restaurants.
Food handlers.
Along with vaccination one should adopt the preventive measures like:
Washing hands thoroughly before eating or preparing food and after using toilet.
Drink clean or treated water.
Avoid raw fruits and vegetables.
Choose hot foods.
Avoid food from street vendors.
Good health practices makes our life more healthier and happier.
Long on the sidelines of its more publicity hungry diseases, typhoid problems need to be tackled immediately 
